• A rare complication of rheumatoid arthritis with autoimmune NEUTROPENIA; and SPLENOMEGALY.
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2025
• A syndrome characterized by the presence of rheumatoid arthritis, splenomegaly, and granulocytopenia. Patients are at an increased risk of infection because of the low white cell counts.
  NCI
  U.S. National Cancer Institute, 2021
• Felty syndrome (FS), also known as ''super rheumatoid'' disease, is a severe form of rheumatoid arthritis (RA), characterized by a triad of RA, splenomegaly and neutropenia, resulting in susceptibility to bacterial infections.
  OrphaNet
  INSERM, 2021
• Felty syndrome (FS), which was first described in 1924, is a potentially serious condition that is associated with seropositive (rheumatoid factor [RF]-positive) rheumatoid arthritis (RA). FS is characterized by the triad of RA, splenomegaly, and granulocytopenia.
  Medscape
  WebMD, 2025
• Felty's syndrome is a rare, potentially serious disorder that is defined by the presence of three conditions: rheumatoid arthritis (RA), an enlarged spleen (splenomegaly) and a decreased white blood cell count (neutropenia), which causes repeated infections. Although some individuals with Felty's syndrome are asymptomatic, others can...
  NIH Genetic and Rare Diseases
  National Center for Advancing Translational Sciences
• First described by A.R. Felty in 1924, Felty syndrome (FS) is a rare, extra-articular manifestation of rheumatoid arthritis. It is characterized by persistent, idiopathic neutropenia and frequently (>90% cases) by splenomegaly. The neutropenia in FS is defined as a neutrophil count <2000/microliter for >6 months.
  Epocrates
  Athenahealth, Inc., 2019